1. Field of the Invention
The present invention relates to an endoscope with various kinds of units fixed to a distal end portion of an insertion portion.
2. Description of the Related Art
As is well known, endoscopes are widely used for observation, treatment and the like inside a body (inside a body cavity) of a living body or for inspection, repair and the like in industrial plant equipment.
On such an endoscope, an image pickup unit in which an objective optical system is arranged, an illumination unit in which an illumination optical system is arranged, a channel unit for a treatment instrument channel, a nozzle unit such as for air/water feeding, and the like are fixed to a distal end portion by screw members.
The various kinds of units are fitted by screwing screws into tapped screw holes made in a distal end portion body provided on the distal end portion of the endoscope, and further bonded and fixed so that the screws do not loosen.
For example, Japanese Patent Application Laid-Open Publication No. H11-244222 discloses a structure for attaching a fluid jet nozzle of an endoscope in which the fluid jet nozzle to be detachably fitted to a distal end rigid portion can be easily attached and detached, and when being fitted, the fluid jet nozzle is fixed firmly in a stable state.